The pedal on my M38 doesn't fully return when I let off of it. If i stick my foot under it and pull up slightly it returns all the way and fully engages. The clutch doesn't slip after that, but it does if I don't pull the pedal up that last half an inch or so. I've replaced the return spring, and greased the 1 fitting I found on the linkage. I think the free play adjustment is ok. Is there anything else I can check without tearing open the clutch?